With fast development of communications technologies, a high speed, a large capacity, and wide coverage have become main characteristics of a modern communications system. Communication ranges are expanded continuously, and communication environments are increasingly complex and diversified, resulting in severe fading, intersymbol interference, and the like. It is particularly important to resolve such non-ideal feature problems.
A multiple-input multiple-output (MIMO) technology, by using resources in a space dimension, allows a signal to obtain an array gain, a multiplexing gain, a diversity gain, and an interference cancellation gain in space, and exponentially increases a capacity and spectral efficiency of the communications system without increasing system bandwidth.
As communication requirements of people on high precision, high reliability, high flexibility, and the like are continuously higher, the modern communications system is always faced with a greater challenge for a larger capacity, wider coverage, and higher speed. One of key technologies and effective means to resolve this problem is to use a transceiver having more antennas, namely, a High Dimensional MIMO (HD-MIMO) system. The HD-MIMO technology can increase the system capacity greatly, and when service requirements (transmission rate, bit error rate, and the like) are low, can reduce a transmit power.
In the prior art, because a quantity of antennas in a conventional MIMO communication scenario is relatively small, and demodulation performance of user data based on an antenna array gain is not improved obviously, only a same power is allocated to a demodulation reference signal resource element (DMRS RE) and a user data RE. In addition, to improve channel estimation performance, in R8, a power of an RE in which a Cell-specific Reference Signal (CRS) is located is increased by using a power of an adjacent user data RE. A premise for implementing this is that a total power of the resource blocks does not change, that is, a power increment on the CRS RE is equal to a power decrement on the other user data.
However, in an HD-MIMO scenario, a high-dimensional antenna configuration provides a capability of sharply reducing a transmit power, and powers of both a user data RE and a DMRS RE are reduced greatly. When an antenna quantity is very large, user data can obtain an array gain of high-dimensional transmit and receive antennas, and an SINR point at which the user data works may be very low; however, a DMRS cannot obtain an array gain of the high-dimensional transmit and receive antennas, and therefore can work only in a region in which an SINR is relatively high. To ensure accuracy of channel estimation at a receive end, a same power is allocated to a DMRS RE and a user data RE, but the power of the user data RE is wasted greatly, and the system cannot fully explore the capability of power reduction, and power utilization is low.